Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Thermal radiation" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 105
Tytuł:
Estimation of internal distribution of temperature inside biological tissues by means of multifrequency microwave thermograph
Autorzy:
Stec, B.
Dobrowolski, A.
Powiązania:
https://bibliotekanauki.pl/articles/308150.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
microwave thermograph
radiometer
thermal radiation
breast carcinoma
Opis:
The paper presents problems connected with thermal radiation of human bodies in microwave range in aspect of diagnosis breast carcinoma. A mathematical model of transmission thermal radiation through tissues is introduced and methods of measurement of temperature, depth and size of heat source, by means of multifrequency microwave thermograph [1 - 7], are described. Theoretical considerations are supplemented with presentation of result experiments.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 1; 39-42
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Novel Method of Thermal Conductivity Measurement Using Stefan-Boltzmann Law
Autorzy:
Leśniewski, W.
Czekaj, E.
Wieliczko, P.
Wawrylak, M.
Powiązania:
https://bibliotekanauki.pl/articles/356312.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal conductivity
thermal radiation
ceramic shell mold
aluminum casting
Opis:
The article presents a novel method that allows measurement of thermal conductivity that is based on Stefan-Boltzmann law. The developed method can be used to determine thermal conductivity of ceramic investment casting molds. The methodology for conducting thermal conductivity tests of ceramic material samples is presented. Knowledge of the value of thermal capacity and thermal conductivity as a function of temperature enables computer simulations of the process of cooling and solidification of liquid metal in a mold.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 311-315
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sposob ochistki krysh ehnergosberegajushhikh teplic ot snega
Method of snow cleaning roof energy-efficient greenhouse
Autorzy:
Opryshko, A.
Pasechnik, H.
Powiązania:
https://bibliotekanauki.pl/articles/77451.pdf
Data publikacji:
2014
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
greenhouse
snow
cleaning
energy efficiency
thermal radiation
analysis
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2014, 16, 3
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined effects of thermal radiation and Hall current on MHD Casson nanofluid exerted by peristaltic transport
Autorzy:
Asha, S. K.
Hadapad, Chandrashekhar
Powiązania:
https://bibliotekanauki.pl/articles/1193365.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Hall current
MHD
nanofluid
peristaltic transport
thermal radiation
Opis:
The present work intends to analyse the MHD Casson nano fluid inside an asymmetric channel. The equations governing the fluid flow admit both Thermophoresis and Brownian motion alongside thermal radiation. We acquired closed form analytical solutions for temperature, axial velocity, nanoparticle concentration and pressure gradient profiles. The ascendency of governing parameters like thermal radiation parameter, thermophoresis, Brownian, Hartmann number and Hall parameter on dimensionless temperature, concentration and pressure gradient profiles have been explained in detailed manner with the aid of plots and table. The prevailed results in this article are verified with prior available literature for specific cases and they are in good agreement.
Źródło:
World Scientific News; 2021, 155; 1-22
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Study of the Heat Loss Attenuation by Clothing on Thermal Manikins Under Radiative Heat Loads
Autorzy:
Den Hartog, E. A.
Havenith, G.
Powiązania:
https://bibliotekanauki.pl/articles/90346.pdf
Data publikacji:
2010
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
protective clothing
heat stress
heat budget models
thermal manikin
thermal radiation
infrared radiation
solar radiation
Opis:
For wearers of protective clothing in radiation environments there are no quantitative guidelines available for the effect of a radiative heat load on heat exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of radiative heat load while wearing protective clothing. As within the ThermProtect project much information has become available from thermal manikin experiments in thermal radiation environments, these sets of experimental data are used to verify the analytical approach. The analytical approach provided a good prediction of the heat loss in the manikin experiments, 95% of the variance was explained by the model. The model has not yet been validated at high radiative heat loads and neglects some physical properties of the radiation emissivity. Still, the analytical approach provides a pragmatic approach and may be useful for practical implementation in protective clothing standards for moderate thermal radiation environments.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2010, 16, 2; 245-261
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of heat transfer on unsteady magnetohydrodynamics (MHD) boundary layer flow of an incompressible fluid a moving vertical plate
Autorzy:
Falodun, B. O.
Fadugba, S. E.
Powiązania:
https://bibliotekanauki.pl/articles/1178267.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Boundary layer
Heat transfer
MHD
Thermal radiation
Viscous dissipation
Opis:
This paper deals with the effects of heat transfer on unsteady MHD boundary layer flow of a chemically reading fluid past a vertical plate in the presence of thermal radiation and viscous dissipation. The governing equations of the problem under investigation are systems of partial differential equations. These equations are namely: continuity equation, linear momentum equation and energy equation. These systems of equations were non-dimentionalized by introducing non-dimensional variables. We resulted to dimensionless systems of partial differential equations. The fluid considered in this paper are optically thick, however we employ the Roseland model. Simulations were done numerically on all controlling parameters and the results generated were displayed in graphs and tables. Results review that thermal Grashof number intensifies the velocity profile and increase in Prandtl number leads to decrease in both the velocity and temperature field. Increasing thermal radiation intensifies the velocity and temperature profile. Thermal radiation speeds up the convection flow and thermal boundary layer of the fluid. Increase in magnetic parameter reduces the velocity profile as a result of the applied transverse magnetic field.
Źródło:
World Scientific News; 2017, 88, 2; 118-137
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady hydromagnetic mixed convection of a radiating and reacting nanofluid in a microchannel with variable properties
Autorzy:
Kefene, Mesfin Zewde
Makinde, Oluwole Daniel
Enyadene, Lemi Guta
Powiązania:
https://bibliotekanauki.pl/articles/38890072.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
nanofluid
mixed convection
permeable microchannel
Buongiorno’s model
thermal radiation
Opis:
Unsteady MHD mixed convection of nanofluid heat transfer in a permeable microchannel with temperature-dependent fluid properties is studied under the influence of a first-order chemical reaction and thermal radiation. The viscosity and thermal conductivity are assumed to be related to temperature exponentially. Using suitable dimensionless variables and parameters, the governing partial differential equations (PDEs) are transformed to their corresponding dimensionless forms solved numerically by a semi-discretization finite difference scheme along with the Runge-Kutta-Fehlberg integration technique. The effects of model parameters on the profiles of velocity, temperature, concentration, skin friction, the Nusselt number, and the Sherwood number are discussed qualitatively with the aid of graph.
Źródło:
Engineering Transactions; 2023, 71, 1; 53-79
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of a steel charge emissivity under strong irradiance conditions
Autorzy:
Benduch, A.
Wyczółkowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/102336.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
porous charge
thermal radiation
thermal resistance
long elements bundles
effective thermal conductivity
radiative thermal conductivity
Opis:
Steel bars are manufactured in the rolling process, whereby they are characterized by strain hardening and poor plastic properties. In many application cases such properties are improper, therefore, additional heat treatment is required. Crucial influence on the products quality after heat treatment has an appropriate selection of process parameters. In many modern technologies of heat treatment the charge of porous structure is subjected to the heating process. Proper control of heat treatment parameters of bundles of rods requires knowledge on their thermal properties. However, it also requires accurate identification of complex heat transfer processes occurring in the porous material. Such analysis, with respect to bundles of bars, provide a response of qualitative nature of the heat exchange area of these charges. The article describes the emissivity measurements of samples of the steel charge using a thermal imaging camera.
Źródło:
Advances in Science and Technology. Research Journal; 2014, 8, 23; 19-25
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Different Analysis of Free Convection Flow and Heat Transfer of Casson Nanofluid over a Vertical Plate under the Influence of Thermal Radiation
Autorzy:
Sobamowo, M. G.
Okolie, A. C.
Powiązania:
https://bibliotekanauki.pl/articles/1193438.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Casson fluid
Free convection
Nanoparticle
Numerical solutions
Prandtl number
Thermal radiation
Opis:
In this paper, a numerical study on free convection flow and heat transfer of Casson nanofluids over a vertical plate under the influence of thermal radiation is carried out. The governing systems of coupled nonlinear partial differential equations of the flow and heat transfer processes are converted to a system of coupled nonlinear ordinary differential equations through suitable similarity variables. The obtained ordinary differential equations are solved using finite difference method. The results of the numerical solutions are compared with the results of past works as presented in literature and good agreement was established. Also, the effects of thermal radiation; Prandtl number, nanoparticles volume-fraction, shape and type on the flow and heat transfer behaviour of various nanofluids over the flat plate are investigated. The results show that the magnitude of velocity near the plate for the Casson nanofluid parameter decreases for increasing value of the Casson parameter, while temperature increases for increase in Casson fluid parameter. Also, the thermal radiation and volume-fraction of the nanoparticles in the base fluid increase, the velocity, temperature, viscous and thermal boundary layers of the nanofluid increase. However, the velocity of the nanofluid decreases as the Prandtl number increases while the temperature of the nanofluid increases as the Prandtl number increases. The velocity of the nanofluid decreases as the volume-fraction or concentration of the nanoparticle in the base fluid increases. The study can benefit the design engineers enhancing their understanding of the phenomenon for various industrial and engineering applications.
Źródło:
World Scientific News; 2021, 157; 38-66
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Passive cooling through the atmospheric window for vehicle temperature control
Autorzy:
Khan, Umara
Zevenhoven, Ron
Powiązania:
https://bibliotekanauki.pl/articles/1955001.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal radiation
passive cooling
vehicle skylight
greenhouse effect
computational fluid dynamics
Opis:
One of the most energy-intensive activities for a vehicle is space air conditioning, for either cooling or heating. Considerable energy savings can be achieved if this can be decoupled from the use of fuel or electricity. This study analyzes the opportunities and effectiveness of deploying the concept of passive cooling through the atmospheric window (i.e. the 8– 14 nm wavelength range where the atmosphere is transparent for thermal radiation) for vehicle temperature control. Recent work at our institute has resulted in a skylight (roof window) design for passive cooling of building space. This should be applicable to vehicles as well, using the same materials and design concept. An overall cooling effect is obtained if outgoing (long wavelength greater than 4 nm) thermal radiation is stronger than the incoming (short wavelength less than 4 nm) thermal radiation. Of particular interest is to quantify the passive cooling of a vehicle parked under direct/indirect sunlight equipped with a small skylight, designed based on earlier designs for buildings. The work involved simulations using commercial computational fluid dynamics software implementing (where possible) wavelengthdependency of thermal radiation properties of materials involved. The findings show that by the use of passive cooling, a temperature difference of up to 7–8 K is obtained with an internal gas flow rate of 0.7 cm/s inside the skylight. A passive cooling effect of almost 27 W/m2 is attainable for summer season in Finland. Comparison of results from Ansys Fluent and COMSOL models shows differences up to about 10 W/m2 in the estimations.
Źródło:
Archives of Thermodynamics; 2021, 42, 3; 25--44
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of microwave radiometers with square - law and linear detectors
Autorzy:
Stec, B.
Dobrowolski, A.
Susek, W.
Powiązania:
https://bibliotekanauki.pl/articles/308204.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
termografia mikrofalowa
radiometr
promieniowanie termiczne
microwave thermograph
radiometer
thermal radiation
sensitivity
Opis:
Stochastic analysis of modulation microwave radiometers with square - law and linear detectors is presented in the paper. Assuming ideal detector characteristics it is shown that in typical applications, i.e., in very low power measurements, a type of detector used is of no influence on total radiometer sensitivity. Other aspects of use of a particular detector are also presented.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 1; 112-116
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady mixed convection nonlinear radiative Casson nanofluid flow with convective boundary condition, heat source and inclined magnetic field effects
Autorzy:
Unyong, Bundit
Govindaraju, Mathialagan
Gunasekaran, Nallappan
Vadivel, Rajarathinam
Powiązania:
https://bibliotekanauki.pl/articles/2141509.pdf
Data publikacji:
2021
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
Casson nanofluid
inclined magnetic field
convective boundary conditions
nonlinear thermal radiation
Opis:
In this paper, we have studied the effect of heat source/sink on unsteady Casson nanofluid past a stretching surface with mixed convection inclined magnetic field and nonlinear thermal radiation numerically. Brownian and thermophoresis effects are studied in this nanofluid model (Buongiorno’s). The governing momentum, energy, and concentration equations are PDEs that are changed into ordinary differential equations by means of suitable transformations. The fourth-order R-K method with shooting technique is adapted to yield the results of this work. The velocity, thermal, and concentration profiles are discussed with the several physical parameters. Also, skin friction, the Nusselt number, and the Sherwood number are examined with the help of the table. It is found that the enhancing value of the unsteady parameter and heat sink parameters reduce the fluid temperature, and the enhancing value of the Casson parameter and heat source parameters increase the fluid temperature. The increasing value of the inclined magnetic field parameter enhances the thermal boundary layer thickness.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2021, 20, 3; 65-76
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of radiating nanofluids mixed convection within concentric pipes filled with a porous medium
Autorzy:
Makinde, Oluwole Daniel
Mabood, Fazle
Khan, Waqar Ahmed
Makinde, Anuoluwa Esther
Powiązania:
https://bibliotekanauki.pl/articles/38910057.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
nanofluid
concentric pipes
mixed convection
thermal radiation
porous medium
entropy analysis
Opis:
In this study, the entropy generation resulting from heat and mass transfer of waterbased nanofluid through an annulus within two concentric vertical pipes filled with a porous medium is investigated. This study considers the effects of thermal radiation, viscous dissipation, thermal buoyancy, and axial pressure gradient in addition to heat and mass transfer. Brownian motion and thermophoresis have been introduced through the Buongiorno model. The similarity solution was used to solve nonlinear ordinary differential equations. The RungeKutta-Fehlberg method is used to solve these equations with the related boundary conditions. The effects of pertinent parameters such as pressure gradient, thermal radiation, viscosity parameter, thermophoretic parameter, Brownian motion parameter, and Eckert number are investigated numerically. This study found that the Bejan number increases as the viscosity parameter increases and decreases as the other active parameters increase. As the radiation parameter, thermophoretic parameter, Brownian parameter, and Eckert number increase, the Nusselt number decreases. The total entropy generation rate is found to increase with the fluid viscosity rate, Grashof number, thermal Biot number, and variable pressure gradient. However, the Bejan number is found to decrease with these parameters, as well as the Prandtl number.
Źródło:
Engineering Transactions; 2023, 71, 3; 419-438
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wielosektorowy promiennik podczerwieni
Multisector IR surface emitter
Autorzy:
Polakowski, H.
Piątkowski, T.
Dulski, R.
Firmanty, K.
Morawski, M.
Powiązania:
https://bibliotekanauki.pl/articles/157679.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
współczynnik emisyjności
promieniowanie cieplne
promieniowanie ciała szarego
kontrast termiczny
emissivity
thermal radiation
gray body radiation
thermal contrast
Opis:
W pracy zaprezentowano wielosektorowy, promiennik podczerwieni, który może być wykorzystany przy badaniach rozdzielczości temperaturowej kamer termowizyjnych. Powierzchnia promieniująca zawiera sekto-ry o różnych współczynnikach emisyjności wykonane z mikrownęk. Umieszczenie wielosektorowego promiennika podczerwieni w odpowied-nio zaprojektowanej osłonie termicznej umożliwia przestrajanie kontrastu sąsiadujących ze sobą sektorów z rozdzielczością bliską 100mK.
The paper presents a multi-sector, highly stable IR source that can be used for (MRTD) testing thermal cameras. The proposed solution is based on a single, monolithic multi-sector IR source with areas of different emissivity. As a result of the emissivity difference, the particular sectors are imaged by thermal camera as areas of different temperatures. The sectors exhibit the radiative properties of a gray body. They are manufactured as micro-cavity structures in a solid metal plate. The desired value of emissivity is achieved by adjusting the geometric parameters of microstructure. The thermal contrast between adjacent sectors is obtained by selecting different effective emissivity values for particular sectors. By placing the multi-sector source inside a thermally insulated case it is possible to tune the thermal contrast between the adjacent sectors with 100 mK resolution. The emissivity of microstructure comb patterns was measured by a thermal camera. The temperature characteristics as well as the relation between the effective emissivity and the shape coefficient of a microstructure were determined. The designed IR source has the uniform radiative temperature distribution across its surface.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 11, 11; 894-897
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiative Falkner-Skan flow of Walter-B fluid with prescribed surface heat flux
Autorzy:
Hayat, T.
Qayyum, S.
Imtiaz, M.
Alsaedi, A.
Powiązania:
https://bibliotekanauki.pl/articles/949144.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Walter-B fluid
Falkner-Skan flow
prescribed surface heat flux
thermal radiation
Opis:
This article addresses the Falkner-Skan flow of an incompressible Walter-B fluid. Fluid flow is caused by a stretching wedge with thermal radiation and prescribed surface heat flux. Appropriate transformations are used to obtain the system of nonlinear ordinary differen- tial equations. Convergent series solutions are obtained by the homotopy analysis method. Influence of pertinent parameters on the velocity, temperature and Nusselt number are in- vestigated. It is observed that by increasing the viscoelastic parameter, the fluid velocity decreases. There is an enhancement of the heat transfer rate for the viscoelastic parameter and power law index. It is also found that the Prandtl number and radiation parameter decrease the heat transfer rate.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 117-127
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 105

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies